The goal of this Phase I design study is to develop the design of an accelerator-based neutron source for clinical boron neutron capture therapy (BNCT) using the compact radio-frequency quadrupole (RFQ) linear accelerator. This accelerator design study will be completed in collaboration with the Brain Tumor Research Center at the University of California in San Francisco (UCSF) and will take into account the new boron compounds being developed at UCSF, as well as the lithium neutron production target and epithermal beam moderator being designed as a part of this collaboration by the Lawrence Livermore National Laboratory. The final RFQ linac design will take advantage of a new superconducting structure if the current required makes a conventional structure too difficult to achieve. The aim of the Phase I program would also be to complete the plans for a Phase II prototype system that could be used in a clinical setting at UCSF to test new targets and moderators, carry out in vitro and in vivo radiobiologic studies on the new boron compounds, and demonstrate the clinical effectiveness of this treatment modality using an accelerator.